Lamp assembly means



Oct. 2, 1934. A, D'OUGLAS 1,975,353

LAMP ASSEMBLY MEANS Filed Jan. 50; 1951 2 Sheets-Sheet 1 Oct. 2, 1934. A DOUGLAS 1,975,353

LAMP ASSEMBLY MEANS Filed Jan. 30, 1931 2 Sheets-Sheet 2 m 9 l6 ZZZ/A05 aw Patented Get. 2, l9 :1

UNITED STATES PATENT OFFICE- '7 Claims.

My invention relates to assembly means for incandescent electric lamps and their mountings and is of particular service where such mountings are in the form of concave reflectors for automobile headlights and the lamps are assembled therewith by means inclusive of sockets. The reflectors are desirably parabolic having openings therethrough through which the sockets.

project.

Among other objects, my invention aims to provide improved means for assuring the assembly of the parts so that the lamps will be properly focused, and when so assembled, maintaining said proper focus with a minimum of parts.

The invention may be understood by reference to the illustrative construction shown in the accompanying drawings, in which- Figure l is a view showing an incandescent lamp and circuit contact terminals in elevation and associated parts in section, of the illustrated embodiment of the invention;

Figure 2 is a side elevation of the socket and a portion of the lamp base, showing associated parts in section;

Figure 3 is a section taken on the line 3-3 of Figure 2;

Figure 4 is a section taken on Figure 3;

Figure 5 is a sectional view of a complete automobile headlight embodying the illustrative construction of my invention;

Figure 6 is a perspective view of a socket and spring embodying my invention assembled as a unit;

Figure 7 is a perspective view illustrating some parts in separated relation; and

Figure 8 is a reduced rear view of the socket and spring as assembled.

The headlight here shown for illustration is inclusive of a parabolic reflector 1 whose reflecting face is covered by a light transmitting closure 2 which may be of glass. This closure is held against the front of the reflector by an assembling ring 3 which also serves to assemble the reflector with a concave back 4. The construction of the peripheral rim portion of the reflector with the back and the construction of the parts 3 and 4 may be of any well known or suitable character and form no novel parts in my present invention, on which account further description of these parts need not be given.

The embodiment of the invention illustrated is inclusive of cylindrical metal lamp sockets 5, each adapted to be passed through a circular opening in the reflector. One of such openings 6 the line 4-4 oi.

in the reflector may be located in the crown of the reflector, and one of the sockets 5 passed therethrough. The opening 6 in the crown of the reflector is essentially circular and of the diameter of thesocket 5 to receive the socket snugly and may be concentric with the principal axis of the reflector. In assembling the socket with the refiector, an inward extension 7 of the portion of the reflector margining the opening 6 passes through the bayonet channel 8, and ultimately, by manipulation of the socket, is received in the innermost seat 9 of the bayonet channel 8. Lugs 10, formed by striking portions of the socket'5 outwardly, are so located on the socket as to pass through lateral enlargements 11 of the opening 6 when the extension '7 is passing through the channel 8. When the extension '7 is seated in the seat 9 and the axis of the socket is coincident with the axis of the reflector, the lugs 10 bear against the reflecting face of the reflector in a plane common to the seat 9 and which plane is perpendicular to the axis of the socket. The lugs 10 together with the seat 9 are thus distributed around the axis of the socket to provide bearing points for the socket on the reflecting surface of the reflector less than 180 degrees apart, in this instance substantially 120 degrees apart, determining, when the bearing points are pressed against the reflector, a position of the socket normal to the reflector.

In assembling the socket 5 with the reflector,

the socket is moved through the opening 6 against the pressure of a spring which is here shown as including a plate 12 having three integral elliptic legs 13. The spring plate 12 has a central aperture 14 which is essentially circular of substantially the diameter of the socket 5. The portion of the plate 12 margining the aperture 14 is inwardly extended as at 15 and these extensions 15 seat in recesses 16 in the rear end of the socket 5. The spring is thus locked to the socket in a plane perpendicular to the socket axis. One of these extensions 15 is desirably larger arcuately than the other two to snugly fit a correspondingly larger recess in the socket, for a purpose presently explained. An insulating contact carrier in the form of a disc 1'? is shown of substantially the size of .the bore of the socket 5. This disc 1'! has segmental shoulders 18 which correspond to the recesses 16 in the rear of the socket 5. When first the plate 12 has its extensions 15 located in the recesses 16 and then the disc 1'7 is located in the bore of the socket outwardly of the plate 12, with the shoulder portions 18 also in the recesses 16, fingers 19 extending longitudinally from the rear end of the socket are turned down to lap the disc 17, holding the disc and plate in place.

The legs 13 of the spring are bent around upon themselves and have free ends which extend toward the socket 5. The terminations of the free ends of the legs 13 are turned slightly toward the forward end of the socket in a reverse curve to each provide bearing points at which the spring presses against the reflector, which bearing points are radially aligned with the bearing points 9, 10, 10 of the socket, as best illustrated in Figure 3. When the socket 5 has been passed through the opening 6 against the pressure of the spring and the extension 7 of the reflector located in the seat 9, with the lugs 10, 10 bearing against the reflecting face of the reflector, the legs 13 of the spring are tensioned against the rear surface of the reflector at points close to the socket 5. The legs 13 are desirably so disposed that when the socket is in final position, the terminations of the legs 13 have been moved toward the socket and press against the rear surface of the reflector at points longitudinally as well as radially aligned with the bearing points 9, 10, 10 of the socket, as best illustrated in Figures 1 and 2. In other words, the legs 13 press against the reflector each at a point substantially directly behind each point 9, 10, 10 and the reflector is clamped between the points 9, 10, 10 and the legs 13, thus preventing the socket axis from being. thrown out of line with the reflector axis as might occur if the spring legs pressed against a portion of the reflector substantially more remote from the socket axis than the bearing points of the socket on the reflector. Furthermore, the reflector is prevented from being dented as frequently occurs when the spring presses against a portion of the reflector which is not being pressed from the other side. Such dents are objectionable since they cause slight humps upon the reflecting face of the reflector which in turn cause distortion of the light beams. Since the spring presses the socket in a plane perpendicular to the socket axis, the socket is maintained normal to the reflector, as well as being positioned axially with respect thereto.

When one of the sockets 5 is located in the crown of the reflector, as shown in Figure 1, its axis may be maintained coincident with the principal axis of the reflector, as already set forth. This result may be further insured, if desired, by flattening a relatively small area of the crown surrounding the socket, in a plane perpendicular to the reflector axis, as shown in the drawings.

In the location in the crown of the reflector, the socket may receive an incandescent lamp 20 having the cylindrical base 21 which is received in the bore of the socket. The base 21 is conveniently provided with lateral enlargements such as the bayonet pins 22, one of which passes through the bayonet channel 8 in the socket and is received in the intermediate seat 23 of the slot 8, while the other bayonet pin passes through a diametrically opposite bayonet channel 24 in the socket 5 and is received in the seat 25 at the inner end thereof. Because the lug 10 which bridges the channel 24 is struck outwardly from the socket, the bayonet pin which is received in the seat 25 is permitted to pass the lug.

The lamp 20 is in this instance a double pole lamp where filament 26 is the bright light producing filament of the lamp, one terminal of which is connected with one of the lamp contacts 27 upon the rear of the lamp base. A filament 28 which is the dim light producing filament of the lamp, is included between the other of the lamp contacts 27 and a metallic sheath which constitutes a part of the lamp baseand to which the filament 26 is also connected. By suitable switching mechanism, not illustrated either the filaments 26 or 28 may be included in circuit or both may be excluded from circuit. Each circuit terminal contact 29 is pressed against its complemental lamp contact 27 to secure the mechanical assembly of the lamp with the socket and also to complete the lamp circuit at the reflector.

One of the shoulder portions 18 of the insulating disc 17 and its corresponding recess in the socket are here shown wider than the others so that the disc 17 can be assembled in only one position rotatively with respect to the socket. Thus the terminal contacts 29 are positively positioned in longitudinal alignment with the lamp contacts 27.

Each terminal contact 29, which is conventionally connected with an insulated current conducting wire 30, is pressed forwardly by a helical coiled spring 31 which surrounds the corresponding stem continuation 32 of each contact 29. Each stem 32 slides within a spring barrel 33 formed integrally with a metallic sleeve 330. carried by the insulating disc 17. The spring 31 presses at one end against the base of the barrel 33 and the other end against a shoulder formed between the contact 29 and the stem 32. 105 Since the lamp base is inserted in the socket against the pressure of the springs 31, the spr ngs 31 press the bayonet pins 22 into engagement with the seats 23 and 25.

The seats 23 and 25 are spaced from the focus 1m of the reflector a distance equal to the distance between the bayonet pins 22 and the lighting center of the bright light producing filament of the lamp 20. The lighting center of the bright light producing filament 26 of the lamp 20 which 1115 is shown upon the axis of the socket when the parts are properly assembled is thus placed exactly upon the focus of the reflector when the bayonet pins 22 are properly seated for the reasons hereinbefore set forth.

When one of the sockets 5 is located to one side of the principal axis of the reflector, it may be provided with a singleterminal contact stem 34 connected with an insulated wire 35 and adapted to be pressed against a single contact on the base of the single pole lamp 36, the lamp being included in circuit by being grounded similarly to the lamp 20, as already described.

The wires 30 and 35 may be carried through the concave back 4 of the headlight to a plugging-in device by which the lamps may be connected with a source of current not shown.

Means are desirably provided for securing the proper intimacy of the lamp base and the socket to further insure coincidence of the lighting center of the lamp filament and the reflector focus, guarding against variations caused by slight differences between the diameters of the bases and the bore of the socket common in commercial practice. In this instance, the wall of the socket 140 5 is split longitudinally as at 37, allowing a slight give to the socket and at the same time, since the socket is formed of resilient metal, providing a segmental portion 38 of the socket connected to the socket along but one side and which func- 145 tions somewhat as a spring tongue. The spring tongue 38 is further defined by longitudinally and transversely extending branches of the bayonet channel 8 the longitudinally extending branch of which is coincident with the split 37. The 50 socket is further formed, as shown, with rigid internal projections such as the longitudinal ribs 39 and 40 spaced substantially 120 degrees apart, and an indentation 41 located on the spring tongue 38 and 120 degrees from each of the ribs 39 and 40. When the base 21 of the lamp 20, for instance, is inserted in the socket 5, the base 21 will be pressed against the ribs 39 and 40 by the spring tongue 38 through the intermediation of the projection 41 on said tongue. Thus a three point bearing is provided for the lamp base in the socket which positions the axis of the lamp substantially exactly upon the axis of the socket regardless of slight variations in the diameters the lamp bases used. The projection 41 is shown at an intermediate point longitudinally of the socket, and desirably mid-way between the inner and outer ends of the ribs 39 and 40, so that the base will be pressed uniformly against the entire length of the ribs 39 and 40. Features of the socket just described-and not herein claimed, are shown and claimed in my copending application Ser. No. 512,374 filed January 30, 1931 which has matured into Patent Number 1,946,197 of Jan. 10, 1934.

The extension 7 of the reflector and the bayonet channel 8 receiving the extension 7, are desirably wider than the bayonet channel 24, so that the socket can be assembled with the reflector in only one way, thus guarding against incorrect assembly, and since the extension 7 must be received in the seat 9 to lock the socket to the reflector, the socket can be assembled in only one position rotatively with respect to the reflector.

The socket desirably cannot be positioned in the reflector with the spring legs 13 bearing against the reflecting face of the reflector.

Obviously, when the extension '7 is seated in the seat 9, the socket cannot be rotated by manipulation of the lamp. It will thus be seen that by my improved assembly means all of the parts, from the terminal contacts in the rear, to the lamp filament in front, are positively aligned with their respective cooperating elements, and the common axis of the parts is positioned and maintained normal to the reflector with a minimum of parts and a minimum of bearing points upon the reflector.

It is preferable to form the socket 5 from a strip of relatively soft metal having some resiliency such as brass which is blanked out and stamped, by appropriate machinery not necessary to be herein described, with the seat 9 and the lugs 10 struck out by a straight line die to cause the bottom of the seat 9 and the bearing surfaces of the lugs 10 to be in a plane perpendicular to the axis of the blank, as described hereinbefore.

Such changes may be made as fall within the scope of the following claims without departing from the invention.

Having thus described my invention, I claim: 1. A lamp receiving socket embodying a metal cylinder adapted to be received in a mounting and to receive a contact carrying base therein, said cylinder being split longitudinally; a bayonet channel in the forward end of said socket, said channel being formed by portions of the cylinder margining the line of said split; an intermediate bayonet seat in said channel and an inner seat at the innermost end of said channel for an extension of said mounting, said intermediate seat and. said inner seat defining a segment of said cylinder forming a spring tongue; an internal projection on said tongue; another bayonet channel diametrically opposite said first bayonet channel; an outwardly struck lugbridging said second bayonet channel; a second outwardly struck lug upon said cylinder spaced substantially 120 degrees from each of the first said lug and the said inner seat, said lugs and said inner seat providing bearing points for said socket on said mounting in a plane perpendicular to the axis of said cylinder; and internal longitudinal ribs in said cylinder spaced substantially 120 degrees from said projection, whereby said base is adapted to be pressed between said projection and said ribs.

2. The structure of claim 1 wherein the projection is substantially midway between the inner and outer ends of said ribs.

3. The structure of claim 1 wherein there is a plate spring surrounding and adapted to press the said bearing points against said mounting.

4. The structure of claim 1 wherein the rear end of the socket carries an insulating contact carrier and wherein there is a spring keyed to the socket and having free portions adapted to press the said bearing points against said mounting, said spring comprising an annulus surrounding the socket and having inwardly extended integral portions received between the socket and said carrier.

5. The combination with a cylindrical resilient metal socket split for its entire length and formed at its forward end with a bayonet channel having longitudinally and transversely extending branches, the longitudinally extending branch of the bayonet channel being coincident with the split in the socket and said branches jointly defining a segmental portion of the socket connected to the socket along but one side; a bayonet seat in the transversely extending branch of the channel; and rigid internal projections in said socket spaced substantially one hundred and twenty degrees apart around the axis of the socket in a common transverse plane passing through said segmental portion.

6. A socket for an electric incandescent lamp comprising a single sheet of metal bent to generally cylindrical form and having at least three bearing surfaces in a common plane perpendicular to the axis of the socket spaced apart about said axis, one of said bearing surfaces being formed by a lug struck outwardly from the body of the socket and attached to the socket at each end transversely of the socket but disconnected from the socket at each side longitudinally of the socket.

7. A metal socket for an electric incandescent lamp comprising a single sheet of metal bent to generally cylindrical form and having three bearing surfaces in a common plane perpendicular to the axis of the socket and in equally spaced apart relation about said axis, two of said bearing surfaces being formed by lugs struck outwardly from the body of the socket and attached to the socket at each end transversely of the socket but disconnected from the socket at each side longitudinally of the socket, and the third bearing surface being formed by a bayonet seat in the body of the socket.

HARRY A. DOUGLAS. 

